Timeliness of Childhood Primary Immunization and Risk Factors Related with Delays: Evidence from the 2014 Zhejiang Provincial Vaccination Coverage Survey

Vaccination coverage survey of children aged 1-3 years in Beijing, China, 2005-2021

BACKGROUND

The routine immunization program for children is a primary strategy and a core part of vaccination. Achieving and maintaining high level of vaccination coverage are important to reduce morbidity and mortality caused by vaccine-preventable diseases. In Beijing, annual coverage surveys have been conducted since 2005. It is necessary and possible to assess the level and trend of routine vaccination coverage of children in Beijing as well as the disruption of coronavirus disease 2019 (COVID-19) pandemic and provide the reference for the further improve the vaccination coverage.

METHODS

The data of 61,521 children aged 1-3 years in the vaccination coverage surveys during 2005-2021 were analyzed by Beijing Center for Disease Control and Prevention. Descriptive epidemiological method was used to analyze the data and the difference of vaccination coverage within the time period.

RESULTS

More than 99 % of participants had immunization cards and electronic immunization records. The concordance rate of both records were also over 99 %. During 2011-2019, the rates of on-time and in-time vaccination of each routine vaccine reached 96 % or more and increased significantly (all P values <0.05), compared with that of 2005-2010. All rates of the investigated vaccine, except for Bacillus Calmette-Guérin vaccine (BCG) and the first dose of hepatitis B vaccine (HepB), decreased in 2020-2021 significantly (all P values <0.05). For the causes of failing to vaccinate on time, delayed vaccination accounted for 47.82 %. The top two vaccines to be missed were the first dose of hepatitis A vaccine and the 4th dose of diphtheria-tetanus-acellular pertussis vaccine, accounting for 21.41 % and 20.79 %, respectively. The main reason for zero-dose/drop-out vaccination was "Guardians regarded the immunization service time as inappropriate", accounting for 72.27 %.

CONCLUSION

The coverage level and service quality of routine immunization in Beijing were relatively high. However, as influenced by COVID-19 epidemics, both on-time and in-time vaccination rates decreased significantly, except for BCG and HepB. Under the background of COVID-19 pandemic, the keys to maintain high level of vaccination coverage include flexible immunization service time to ensure the guardians bringing their children for vaccination timely, and more attention from providers to the doses after children's first birthday.

Comparing the effect of parental education via both lecture and film upon vaccination uptake for children under one year of age: A cluster randomized clinical trial

BACKGROUND AND AIM

Vaccination is the most cost-effective action in preventing infectious diseases. Despite Iran's success in high vaccination coverage, in some areas there is a delay in vaccination. The aim of this study was to determine and compare the effect of education on immunization via lecture and film upon parental delay in vaccination uptake for children under 12 months of age.

METHODS

A multicentre cluster-randomized clinical trial with comprehensive urban health centres (CUHCs) in Shooshtar city, Khuzestan province, Iran as the unit of randomization was conducted. Overall, 8 CUHCs were randomized to receive education either via film (n = 165) or lecture (n = 164). In order to assign CUHCs to two groups, a simple random sampling method of coin tossing was used. Parents with children under 12 months and with a history of delayed vaccination were included in the study. Consecutive sampling was performed until the number needed for the cluster was reached. Interventions were delivered in small groups of 5-8 participants. Demographical data and clinical histories were collected from parents directly via a personal characteristic's questionnaire. Clinical data was extracted from vaccination records, the child's vaccine card and the vaccine information registration system. Statistical analyses of intervention effects were performed as per-protocol analysis.

RESULTS

In terms of individual characteristics and vaccine information significant differences between the two groups were only observed in relation to the parent of the participant, the child's gender, the number of children in the family, and timely injection of the vaccine in the previous child (p < 0.05). The chance of delay in vaccination after the intervention, without and considering the effect of intervening variables was 78 % and 74 % higher in the lecture group than in the film group, respectively (OR = 1.786, CI = 1.152-2.774 vs AOR = 1.743, CI = 1.011-3.007). Overall, 37.6 % of children in the film-based education group and 51.8 % of children in the lecture-based education group received their next vaccine with a delay of more than 7 days.

CONCLUSION

Education delivered via film can reduce the delay in vaccination more effectively. These findings, along with those of other studies conducted around the world suggest that multimedia education should be considered more widely in the field of education in children's vaccination.

Factors related to parents’ adherence to childhood immunization

Background

Immunizations protect children from deadly infectious diseases. Yet, there is still insufficient understanding of the factors associated with parents’ non-adherence to immunizations in contexts outside of Western countries. The aim of this study is twofold: (a) to investigate non-adherence to immunizations for children aged 6 months to 6 years in Saudi Arabia based on the number of immunizations missing or delayed by more than one month; and (b) to examine the underlying factors that predict the extent of non-adherence based on the Health Belief Model framework.

Methods

A cross-sectional study was carried out in 22 randomly selected primary health care centers. Structured interviews were also conducted to collect data using the modified Health Belief Model questionnaire. Multiple regression analysis was used to assess the predictors of the extent of non-adherence.

Results

Based on data from 220 participants, 51.8% of parents did not adhere with childhood immunizations. There was no significant relationship between parents’ sociodemographic characteristics and the extent of their hesitancy about children’s immunizations. The linear combination of perception of infectious disease severity, perception of their children’s susceptibility, perception of immunization benefits, perception of fewer barriers to obtaining immunizations, cues to action related to immunizations, and self-efficacy predicted the extent of non-adherence to immunizations (F (11.220) = 2.595, p < 0.001) and explained 12% of its variance. Yet, only perceived children’s susceptibility, perceived barriers, and self-efficacy independently predicted parents’ non-adherence.

Conclusion

Saudi Arabia’s high proportion of non-adherence to childhood immunizations should be addressed. For instance, a health education program could be developed to increase parents’ awareness that their children are susceptible to health risks. Paying a special attention to existing barriers in accessing and receiving the immunizations is crucial. In addition, building parents’ self-efficacy, which is confident in making healthy decisions, such as keeping their children’s immunizations up to date, is important.

Delays in routine childhood vaccinations and their relationship with parental vaccine hesitancy: a cross-sectional study in Wuxi, China

OBJECTIVES

This study aimed to examine childhood vaccination delay, explore the association between vaccination delay and parental vaccine hesitancy, and assess childhood vaccination delays during the coronavirus disease (COVID)-19 pandemic in China.

METHODS

This cross-sectional survey was conducted in Wuxi City. Participants were recruited from local vaccination clinics. Questionnaires were used to collect information about socio-demographics, vaccine hesitancy, and immunization clinic evaluations. Vaccination records were obtained from the Jiangsu Information Management System of Vaccination Cases.

RESULTS

Overall, 2728 participants were included. The coverage for seven category A vaccines (Expanded Program on Immunization (EPI)) was more than 95% at 24 months. The proportion of children vaccinated in a timely manner was the highest for the first dose of the hepatitis B vaccine (91.6%) and the lowest for the Bacillus-Calmette-Guerin vaccine (44.6%). More than 50% of the planned vaccinations were delayed in February and March 2020. The Vaccine Hesitancy Scale scores were not associated with vaccination delay (P = 0.842). Children's vaccination delays were negatively associated with parents who reported convenient access to clinics and satisfaction with immunization services (P = 0.020, P = 0.045).

CONCLUSIONS

EPI is highly successful in China. Despite vaccination delays due to the COVID-19 pandemic, coverage was recovered after lockdown restrictions were eased.

Evaluating the vaccination coverage: validity of household-hold vaccination booklet and caregiver's recall

BACKGROUND

We compared results from household data sources to medical record sources by using data from a vaccination coverage survey.

METHODS

Vaccination coverage (VC) was calculated based on parental recall, household vaccination booklet, and Zhejiang provincial immunization information system (ZJIIS). We evaluated the accuracy of VC based on household sources (vaccination booklet and recall) assuming the medical record was accurate. Concordance, sensitivity, specificity, positive predictive value, and negative predictive value were estimated as well as the Kappa statistic was also used to evaluate the agreement between data sources.

RESULTS

Among the 1,800 children identified in the household survey, all were registered in ZJIIS. VC estimated using the vaccination booklet alone was substantially lower than that based on medical records (net bias 3.4-16.7% in different age groups). VC based on parental recall ranged from 2.5% below (among children aged 1 year) to 16.7% points above (among children aged 6 years) than those based on medical records. Concordance was lowest for card estimates (32.5-45.5%). Sensitivity was <60% for all household sources, except for recall source. Specificity was lowest for recall estimates (14.5-42.6%). Positive predictive value was >75%, while negative predictive value was <50%, for all household sources. Kappa statistics generally indicated poor agreement between household and medical record sources.

CONCLUSIONS

Household-retained vaccination booklets and parental recall were insufficient sources for evaluating the VC. Our findings emphasized the importance of taking interventions to make the vaccination booklet more consistent with the records from medical resource.

Measles vaccination among children in border areas of Yunnan Province, Southwest China

BACKGROUND

Border areas are at high risk of measles epidemics. This study aimed to evaluate the effectiveness of the implementation of the routine two-dose measles containing vaccine (MCV) program in border counties of Southwest China.

METHODS

Data used in the study were derived from a cross-sectional survey among 1,467 children aged 8 to 84 months from five border counties of Yunnan Province, Southwest China in 2016. The participants were recruited using a multistage sampling method. Primary guardians of the children were interviewed to collect information on vaccination history, socio-economic status, and knowledge about immunization. Both coverage and timely coverage for the first (MCV1) and the second (MCV2) dose of MCV were calculated. The Kaplan-Meier method was performed to estimate the cumulative coverage of MCV, and Log-rank tests were adopted to compare the differences across counties and birth cohorts. Univariate and multivariate logistic regression models were used to investigate the predictors of delayed MCV1 vaccination.

RESULTS

The coverage for MCV1 and MCV2 were 97.5% and 93.4%, respectively. However, only 63.8% and 84.0% of the children received MCV1 or MCV2 on time. Significant differences in the cumulative coverage were detected across counties and birth cohorts. Results of the multivariate logistic regression analysis indicated that children whose primary guardian knew the schedule of MCV were less likely to receive MCV1 late (OR = 0.63, P<0.01). For the guardians, doctors at vaccination units were the primary and also the most desired source of vaccination information.

CONCLUSIONS

Although the coverage for MCV is high in border areas of Southwest China, the timeliness of MCV vaccination seems suboptimal. Tailored information from local health professionals may help to reduce untimely vaccination.

Resources for assessing parents' vaccine hesitancy: a systematic review of the literature

The concept of Vaccine Hesitancy has begun to appear in the scientific landscape, referring to the reluctance of a growing proportion of people to accept the vaccination offer. A variety of factors were identified as being associated with vaccine hesitancy but there was no universal algorithm and currently there aren’t any established metrics to assess either the presence or impact of vaccine hesitancy. The aim of this study was to systematically review the published questionnaires evaluating parental vaccine hesitancy, to highlight the differences among these surveys and offer a general overview on this matter. This study offers a deeper perspective on the available questionnaires, helping future researches to identify the most suitable one according to their own aim and study setting.

Timeliness of routine vaccination among children and determinants associated with age-appropriate vaccination in Mongolia

Introduction

Routine vaccination at the recommended age is crucial to minimize the risk of acquiring vaccine preventable diseases. This study aimed to assess the proportion of children receiving routine immunization at the recommended age and determinants of timely (age-appropriate) vaccination in Mongolia.

Material and method

A total of 879 eligible children aged 12-23 months were included in this study. We investigated age-appropriate administration of Bacillus Calmette-Guerin vaccine (BCG); hepatitis B vaccine (Hep B); oral polio vaccine (OPV); pentavalent vaccine; and measles, mumps, and rubella vaccine (MMR) using Kaplan-Meier method. Multilevel logistic regression with random intercept at cluster level was used to assess the determinants of age-appropriate vaccination.

Results

Overall, the crude vaccination coverage for routine vaccinations were above 90% for all vaccines except MMR1 which was 86.0% (95% CI, 83.6-88.2). While the first dose of almost all the vaccines given at birth; BCG, Hep B, and OPV0, were administered in a timely manner, a substantial proportion of second and third doses of these vaccines were not given in a timely manner with age-appropriate vaccination coverage ranging from 35.9% (32.8-39.1%) for MMR1 to 67.7% (64.5-70.7%) for OPV1 respectively. Factors associated with age-appropriate administration of the investigated vaccines included socio-economic status of household, religion of household heads, area of residence, owning mobile phone, and season of childbirth. For instance, children belonging to households from richer wealth quintile had higher possibilities of getting age-appropriate OPV1-OPV3, PE1-PE3 and MMR1 vaccines compared to those from the poorest household wealth quintile.

Conclusion

Our findings suggest that the commonly used indicator 'crude vaccination coverage' could be supplemented by 'age-appropriate vaccination' to help to identify gaps in timely vaccinations and stimulate interventions in Mongolia. Factors such as household wealth quintile, place of residence and religion associated with timely vaccination in our study could be considered to promote effective intervention aiming to improve adequate vaccination coverage.

Characterizing mothers and children at risk of being under-immunized in India: A latent class analysis approach

OBJECTIVES

While India has made substantial progress in introducing new vaccines and scaling up immunization coverage, inequities persist sub-nationally. This study was performed to investigate the risk of under-immunization based on class membership and to identify heterogeneous classes based on sociodemographic characteristics in pediatric and maternal populations in India through latent class analysis.

METHODS

Data from the most recent National Family Health Survey conducted in 2015-2016 were used. Latent class analysis was used to model immunization coverage in children aged 12-23 months and mothers, and to identify subgroups to characterize those at risk of not being immunized.

RESULTS

Patterns of sociodemographic characteristics were found to contribute to non-immunization or under-immunization among pediatric and maternal populations in India. Individuals who fit into one of three categories were identified in both populations: those at high, medium, and lower risk of not being immunized. Lower socioeconomic status, lack of antenatal care, and lower maternal education put individuals at higher risk of not being immunized with routine childhood vaccines and maternal tetanus toxoid.

CONCLUSIONS

Predisposing risk factors can persistently impact immunization status despite improvements in immunization access in India. Tailored programmatic interventions should be developed to improve immunization coverage among those children and mothers who are at highest risk of being under-immunized or not immunized.

Timely completion of vaccination and its determinants among children in northwest, Ethiopia: a multilevel analysis

BACKGROUND

Timely vaccination is key to prevent unnecessary childhood mortality from vaccine-preventable diseases. Despite the substantial efforts to improve vaccination completeness, the effort towards timeliness of vaccination is limited with non-attendance and delays to vaccination appointments remaining a big challenge in developing countries. There is also a limited evidence on timeliness of vaccination. Therefore, this study aimed to determine the magnitude and associated factors for timely completion of vaccination among children in Gondar city administration, north-west, Ethiopia.

METHOD

This study employed a community-based cross sectional study design. A sample size of 821 children aged 12 to 23 months were considered. Two stages random sampling technique was used to select study subjects. To account the effect of clustering, bivariable and multivariable multilevel logistic regression analysis were applied. The measures of association estimates were expressed as adjusted odds ratio (AOR) with their 95% confidence intervals (CIs).

RESULTS

Of the 774 children included for analysis, 498 (64.3%) were fully vaccinated while 247 (31.9%) were fully vaccinated on-time. Caregivers who had secondary education and above (AOR = 2.391; 95% CI: 1.317-4.343), from richest households (AOR = 2.381; 95% CI: 1.502-3.773), children whose mother attended four or more ante natal care visits (AOR = 2.844; 95% CI: 1.310-6.174) and whose mother had two or more post natal care visits (AOR = 2.054; 95%CI:1.377-3.063) were positively associated with on-time full vaccination. In contrary, caregivers aged above 35 years (AOR = 0.469; 95 % CI: 0.253-0.869], being vaccinated at health post (AOR = 0.144; 95%CI: 0.048-0.428) and travelling more than 30 min to the vaccination site (AOR = 0.158; 95%CI: 0.033-0.739) were negatively associated with on-time full vaccination. The random effects indicated that 26% of the variability in on-time full vaccination was attributable to differences between communities.

CONCLUSION

In this study, untimely vaccination was found to be high. Different individual and contextual factors were found to be associated with on-time full vaccination. Therefore, tailored strategies have to be designed and implemented to address people and the communities where they live. Moreover, timeliness of vaccination should be considered as important indicator of the immunization program performance in Ethiopia.

EPI immunization coverage, timeliness and dropout rate among children in a West Cameroon health district: a cross sectional study

BACKGROUND

Monitoring of the expanded program on immunization's performance is not only limited to routine periodic reports but equally includes surveys. Based on unpublished national EPI surveillance data from the past 5 years in Cameroon, the Foumban health district has reported a high number of vaccine preventable disease suspected cases. Contradictory information on the immunization coverage in this district exists from both administrative data and published literature. As a result, the objective of this study was to estimate the immunization coverage and dropout rate in age group 12-23 months and timeliness in age group 0-59 months among children in Foumban Health District (Cameroon), in 2018.

METHOD

This was a descriptive cross-sectional study targeting randomly selected children aged 0-59 months from Foumban health district. Data were collected by trained and supervised surveyors using a pretested questionnaire to describe the immunization coverage, timeliness and dropout rate in eighty clusters of about thirty buildings selected by stratified random sampling in July 2018.

RESULTS

In total, 80 clusters covering 2121 buildings were selected and all were reached (100%). A total of 1549 (81.2%) households accepted to participate in the survey and 1430 children aged 0-59 months including 294 (20.6%) aged 12-23 months were enrolled into the study. Of these 1430 children, 427 [29.9 (27.4-32.2)%] aged 0-59 months were vaccinated with evidence. In the age group 12-23 months, the immunization coverage with evidence of BCG, DPT-Hi + Hb 3 and measles/rubella were 28.6(23.4-33.9)%, 22.8 (18.1-27.6)% and 14.3 (10.3-18.1)% respectively. Within age group 0-59 months; the proportion of children who missed their vaccination appointments increased from 23.3 to 31.7% for the vaccine planned at birth (BCG) and last vaccine planned (Measles/Rubella) for the EPI program respectively. In age group 12-23 months; the specific (DPT-Hi + Hb1-3) and general (BCG-Measles/Rubella) dropout rates of vaccination with evidence were 14.1 and 50.0% respectively.

CONCLUSION

Documented immunization coverage, dropout rate and timeliness in Foumban Health district are lower than that targeted by the Cameroon EPI. Competent health authorities have to take necessary actions to ensure the implementation of national guidelines with regards to children access to immunization. Also, studies have to be conducted to identify determinants of low immunization coverage and delays in immunization schedules as well as high dropout rates.

Analyzing the Urban-Rural Vaccination Coverage Disparity through a Fair Decomposition in Zhejiang Province, China

Objectives: Exploring determinants underlying disparities in full vaccination coverage (FVC) can contribute to improved immunization interventions. FVC and its risk factors in Zhejiang province have been studied, yet the determinants explaining the rural-urban disparity in FVC have not been studied. This study aimed to disentangle the factors explaining rural-urban disparities in FVC of vaccine doses scheduled during the first year of life in Zhejiang province. Methods: We used data from a vaccination coverage survey among children aged 24-35 months conducted in 2016. The outcome measure was full vaccination status, and the grouping variable was the area of residence. Descriptive statistics were used to analyze the FVC and rural-urban residence across the exposure variables. The Fairlie decomposition technique was used to decompose factors contributing to explaining the FVC disparity. Results: There were 847 children included in this study, of which 49.6% lived in a rural area. FVC was 94% in rural areas and 85% in urban areas. A disparity of 9% to the advantage of the rural areas and the exposure variables explained 81.1% of the disparity. Maternal factors explained 49.7% of the explained disparity with education, occupation, and ethnicity being the significant contributors to the explained disparity. Children's birth order and immigration status contributed somewhat to the explained inequality. Conclusion: There was a significant disparity in FVC in Zhejiang province, a disadvantage to the urban areas. Policy recommendations or health interventions to reduce the inequality should be focused on eliminating poverty and women's illiteracy, targeted at migrant children or children from minority ethnicities.

Determinants of timeliness in early childhood vaccination among mothers with vaccination cards in Sindh province, Pakistan: a secondary analysis of cross-sectional survey data

OBJECTIVE

Untimely vaccination refers to receiving the given dose before (early) or after (delayed) the recommended time window. The purpose of this study was to assess the extent of timeliness of childhood vaccinations and examine the determinants of vaccination timeliness in Sindh province, Pakistan.

DESIGN

Cross-sectional analysis of data from the 2013 and 2014 Maternal and Child Health Program Indicator Surveys.

SETTING

Community-based maternal and child health surveys.

PARTICIPANTS

Among 10 200 respondents of Maternal and Child Health Program Indicator Surveys, 1143 women who had a live birth in the 2 years preceding the survey were included.

OUTCOMES

At the participants' home, an interviewer asked mothers to show their children's vaccination cards, which contained information regarding vaccinations. Children's vaccination status was categorised into timely or early/delayed compared with vaccination schedule. A logistic regression analysis using Firth's penalised likelihood was performed to identify factors associated with timeliness of vaccinations.

RESULTS

238 children (20.8% of children who received a full set of basic vaccinations) received all vaccinations on schedule among children who received a full set of basic vaccinations. The percentages of timely vaccinations ranged from 2.3% for second measles vaccination to 89.3% for bacillus Calmette-Guérin. Child's age and place of delivery were associated with timely vaccinations. Older child age and institutional delivery were associated with decreased timely vaccination rate.

CONCLUSIONS

Home-based vaccination record is a key tool to improve the timeliness of vaccinations. The redesigned vaccination cards, the new electronic registries for vaccination card information and the vaccination tracking system to remind the second/third vaccination visits may be helpful to improve timely vaccinations for children under 2 years old.

Age-appropriate vaccination coverage and its associated factors for pentavalent 1-3 and measles vaccine doses, in northeast Ethiopia: A community-based cross-sectional study

BACKGROUND

In Ethiopia, there are limited studies on age-appropriate vaccinations that children received at the recommended specific ages. Therefore, we assessed age-appropriate vaccinations coverage and its associated factors among children 12 to 23 months of age in Menz Lalo district, northeast Ethiopia.

METHODS

A community-based cross-sectional study was conducted in Menz Lalo district from March to April/2018 among 417 mothers/caregivers with children 12 to 23 months of age using simple random sampling technique. Data were collected using a pretested structured questionnaire. Information about children's vaccination status was collected from vaccination cards. Age-appropriate vaccination coverage was measured using World Health Organization vaccination schedule recommendation. Data was entered into Epi-Info7 software and exported to SPSS-20 for analysis. Four consecutive logistic regression models were performed to identify factors associated with age-inappropriate vaccinations. A P-value of ≤ 0.05 was considered to state statistically significant associations.

RESULTS

Age-appropriate vaccination coverage was 39.1% (95% CI: 34.3 to 44) for pentavalent 1, 36.3% (95% CI: 31.6 to 41.5) for pentavalent 2, 30.3% (95% CI: 25.6 to 35) for pentavalent 3 and 26.4% (95% CI: 21.7 to 31) for measles vaccine doses. Age-inappropriate pentavalent 1-3 vaccinations was associated with being male sex (AOR: 0.47, 95% CI: 0.29-0.74), lack of telephone (AOR: 2.2, 95% CI: 1.4-3.6), lack of usual caretaker (AOR: 2.6, 95% CI: 1.3-5.2), unplanned pregnancy (AOR: 1.9, 95% CI: 1.1-3.5), missing pregnant women's conference (AOR: 2.7, 95% CI: 1.3-5.7), decreasing birth order (AOR: 0.34, 95% CI: 0.17-0.68) and insufficient knowledge (AOR: 2.7, 95% CI: 1.6-4.4).

CONCLUSION

The proportions of age-appropriate vaccination coverage were low in the study area. Modifiable factors were associated with age-inappropriate vaccinations. Vaccination interventions should consider identified modifiable factors to improve age-appropriate vaccinations coverage.

Vaccination timeliness and delay in low- and middle-income countries: a systematic review of the literature, 2007-2017

Background: Traditional measurements of vaccine coverage at specific ages can mask poor vaccine timeliness. However, optimal measurement of timing is unclear due to variations in countries’ recommended vaccination schedules and lack of a commonly accepted standard for “timeliness”. We conducted a systematic review of literature on vaccine timeliness and delay in low- and middle-income countries from 2007 to 2017.

Methods: A search of articles published between January 1 2007 and December 31 2017, was performed in PubMed, EBSCOhost, and Embase.

Results: 67 papers were included, of which 83% used a categorical measure of delay and 41% evaluated continuous delay. The most common age at assessment was 1 month, with earlier age benchmarks typically used with birth doses.

Conclusions: Categorical definitions of vaccination timing vary widely, with benchmarks of delay varying from days to weeks to months. Use of a continuous measure of vaccine delay may be more informative and comparable.

Reliability and validity of a survey to identify vaccine hesitancy among parents in Changxing county, Zhejiang province

BACKGROUND

To evaluate the validity and reliability of a survey to identify vaccine hesitancy among parents.

METHODS

Cross-sectional survey of parents of 19-35 month old children was conducted in Changxing County, Zhejiang Province, through a questionnaire developed for the survey of the vaccine hesitancy. Construct validity was assessed by linking parental responses to their child's immunization record. The association between mean% of days of under-immunization and the parental socio-demographics and the individual item response was explored via the univariate and multivariate analyses. Factor analysis was applied to confirm survey sub-domains and Cronbach's α to determine the internal consistency reliability of sub-domain scales.

RESULTS

We approached 336 households while 285 of them agreed to participate in this study. Education level and the parental 'score of vaccination hesitancy' were significantly associated with the mean% of days of under-immunization. Cronbach's coefficients for the 3 sub-domain scales created by re-grouping the questionnaire's items were 0.71, 0.83, and 0.72, respectively.

CONCLUSIONS

The survey represented a valid and reliable instrument to identify VHPs and it could help to screen parents to receive an intervention aimed at increasing acceptance of vaccinations.

Validity of Maternal Recall to Assess Vaccination Coverage: Evidence from Six Districts in Zhejiang Province, China

Background: Although recall-based data are collected by survey when the vaccination records are not available, the preferred estimates remain the record-based ones due to the limited validity of recall-based data. However, the evidence on validity of maternal recalls is limited and varied across vaccine types. To close the gaps, we validated the maternal recall on vaccination against record-based data in six districts in Zhejiang Province, China. Methods: We used a cross-sectional survey of about 648 households with mothers who delivered in the last 12 months prior to the survey in October 2017, from six districts in Zhejiang Province. Vaccination status on five vaccine types scheduled before 12 months of age were collected through maternal recall and vaccination records. The level of agreement and recall bias between the two resources, the sensitivity and specificity of maternal recall were evaluated. Risk factors for maternal recall bias were also identified through logistic regression model for each type of vaccine. Results: The level of agreement between recall and record was above 90% across vaccine types, with the recall bias ranged from 2.2% to 9.7%. Recall bias due to over-reporting was slightly higher than that due to under-reporting. Recall bias was positively associated with high parity, home delivery, younger mothers, mothers with low education, and migrant mothers. Conclusions: This study indicated most of the vaccination status across vaccine types was accurately identified through maternal recall and supported the use of maternal recall to estimate the vaccination coverage as an alternative in the absence of record-based data.

Inequities in Childhood Vaccination Coverage in Zhejiang, Province: Evidence from a Decomposition Analysis on Two-Round Surveys

Objective: The objectives of this study were to determine the degree and risk factors of the inequity in the childhood coverage of full primary immunization (FPI) in Zhejiang province. Method: We used data from two rounds of vaccination coverage surveys among children aged 24–35 months conducted in 2014 and 2017, respectively. The household income per month was used as an index of socioeconomic status for the inequality analysis. The concentration index (CI) was used to quantify the degree of inequality, and the decomposition approach was applied to quantify the contributions from demographic factors to inequality in the coverage of FPI. Results: The coverage rates of FPI were 80.6%, with a CI value of 0.12028 for the 2014 survey, while the coverage rates of FPI were 85.2%, with a CI value of 0.10129 for the 2017 survey. The results of decomposition analysis suggested that 68.2% and 67.1% of the socioeconomic inequality in the coverage of FPI could be explained by the mother’s education level for the 2014 and 2017 survey, respectively. Other risk factors including birth order, ethnic group, mother’s age, maternal employment status, residence, immigration status, GDP per-capita, and the percentage of the total health spending allocated to public health could also explain this inequality. Conclusion: The socioeconomic inequity in the coverage of FPI still remained, although this gap was reduced between 2014 and 2017. Policy recommendations for health interventions on reducing the inequality in the coverage of FPI should be focused on eliminating poverty and women’s illiteracy.

An Overview of Coverage of BCG Vaccination and Its Determinants Based on Data from the Coverage Survey in Zhejiang Province

To assess the Bacille Calmette-Guérin (BCG) vaccination coverage in Zhejiang province and to investigate predictors of the BCG vaccination, we used data from the 2017 Zhejiang provincial coverage survey. Demographic and immunization data on the selected children, their mothers, and their families were also collected by using a pre-tested questionnaire. BCG scars were verified among children who were available at the moment of survey. Coverage of BCG and other expanded program on immunization (EPI) vaccines scheduled before the first year of life was calculated. BCG coverage through the scar assessment and timeliness of BCG were also presented. Multivariate analyses of the predictors associated with the BCG vaccination and its timeliness were conducted separately. In total, 1393 children agreed to participate in the survey and presented the immunization cards. Of them, the coverage of BCG was 92.0% and 88.3% received the BCG within the first 28 days after birth. Besides this, 1282 out of the 1393 children were screened for the BCG scars and 97.1% of them had developed the scars. The multivariable logistic regression analyses indicated that hospital delivery, higher maternal education, a mother with no job, and a resident child were positively associated with the higher BCG vaccination coverage and its timely administrations. BCG coverage was optimal and it was administered in a timely manner. The majority of children vaccinated with BCG developed scars. Tailored interventions should be more greatly focused on and targeted to children with the risk factors identified in this study.

Improved timely birth dose coverage of hepatitis B vaccine narrows the socio-economic inequality in western China in 2011-2016

OBJECTIVE

To compare timely birth dose (TBD) coverage of hepatitis B vaccine and socio-economic inequality distribution of TBD coverage between 2011 and 2016 in rural areas of western China.

METHODS

In western China, using multi-stage probability proportion to size sampling, 2633 and 1929 children aged 0-35 months with an immunization card were selected from 14 rural counties in 2011 and 2016, respectively. Socio-economic characteristics were obtained from face-to-face questionnaire survey and copies of vaccination certificates. We performed multivariate logistic regression models to identify the determinants of TBD coverage of hepatitis B vaccine. We grouped TBD coverage by wealth quintiles, calculated inequality using the difference base on coverage in richest (quintile 5) and poorest (quintile 1) household wealth quintiles.

FINDINGS

From 2011 to 2016, the overall TBD coverage of hepatitis B vaccine among children aged 0-35 months in rural areas of western China increased from 52.8% (95% confidence interval, CI: 42.4-62.8) to 80.2% (95% CI: 69.5-87.8). The absolute difference in TBD coverage between richest and poorest quintiles was 20.6 (95%CI: 9.4-31.8) and 15.8 (95%CI: 1.4-30.2) in 2011 and 2016, respectively.

CONCLUSION

The socioeconomic inequality in TBD coverage decreased over the study period, but such inequality still existed in 2016. To improve inequality in TBD, the government should pay more attention to the disadvantaged groups, especially the children who were delivered at home, or whose caregivers were ethnic minority or who have a lower level of education.

How often do children receive their vaccinations late, and why?

OBJECTIVES

To assess vaccination timeliness, risk factors associated with delays and the reasons for delayed vaccinations among children below the age of 3 years in Jeddah, Kingdom of Saudi Arabia.

METHODS

This is a cross-sectional study conducted in Jeddah, Saudi Arabia during the period of May 2016 to August 2017. Data were obtained from parents of children under the age of 3 years using a structured questionnaire comprised of questions about sociodemographics, physical well-being of the child and the reasons that are used to justify delayed vaccinations. Vaccinations were considered delayed if they occurred more than 30 days after the time designated on the primary vaccination schedule. Logistic regression was used to assess the risk factors for vaccination delays.

RESULTS

The study included 351 children. Delayed vaccinations were observed in 85/351 (24.2%) of the sample. Delays were noted to occur most frequently for Measles, Mumps, Rubella vaccine (MMR), seconddose of meningococcal conjugate quadrivalent vaccine (MCV4), second  dose of oral polio vaccine (OPV) and fourth  dose of pneumococcal conjugate vaccine (PCV) in 19/125 (15.2%) of the sample. Traveling at the time of vaccination was the most common delay reason and was reported in 31/142 (21.3%) of the sample.

CONCLUSION

Adherence to vaccination is fairly common in this part of the country. However, vaccination delays are still present and should be addressed to improve health care.